OPTICAL MULTIPLEXER AND DEMULTIPLEXER

摘要

PURPOSE:To eliminate the influence of the chromatic aberration of a near parabolic rod lens and to obtain an optical multiplexer and demultiplexer which can be easily produced and has good mass productivity by slanting the top end face of an optical fiber bundle and bringing the top end face thereof and the near parabolic rod lens into tight contact with each other via a transparent body side in such a manner that the optical axes thereof align to each other. CONSTITUTION:The light of the wavelength lambda1 emitted from an optical fiber 11 passes the transparent body side 21 and is converted by the near parabolic rod lens 15 according to an optical path 18 to parallel light which is then reflected by an interference film filter 16 for reflecting the light of the wavelength lambda1. This light passes again through the lens 15 and advances so as to be focused along an optical path 19. The advancing light is made incident on an optical fiber 12 in the position symmetrical to the fiber 11 relative to the central axis of the lens 15. On the other hand the light of the wavelength lambda2 (lambda1<lambda2) emitted from the fiber 11 advances in the lens 15 along the path 18 like the wavelength lambda1 but passes through the filter 16 with substantially no loss, is reflected by a reflecting mirror 17, focuses again by the lens 15 along an optical path 20 and is made incident on an optical fiber 13.